Piezoelectric thin film-stacked body, piezoelectric thin film substrate, piezoelectric thin film device, piezoelectric actuator, piezoelectric sensor, head assembly, head stack assembly, hard disk drive, printer head, and ink-jet printer device

Abstract

A piezoelectric thin film-stacked body is provided. A piezoelectric thin film-stacked body has a first electrode layer, a first intermediate layer stacked on the first electrode layer, a second intermediate layer stacked on the first intermediate layer, and a piezoelectric thin film stacked on the second intermediate layer, the first intermediate layer includes K, Na, and Nb, the second intermediate layer is a layer causing stress in a compression direction in the piezoelectric thin film, and the piezoelectric thin film includes (K,Na)NbO3.

What is claimed is: 
     
       1. A piezoelectric thin film-stacked body, comprising:
 a first electrode layer; 
 a first intermediate layer stacked on the first electrode layer; 
 a second intermediate layer stacked on the first intermediate layer; and 
 a piezoelectric thin film stacked on the second intermediate layer, 
 wherein the first intermediate layer includes K, Na and Nb, 
 the second intermediate layer is a layer causing stress in a compression direction in the piezoelectric thin film, and 
 the piezoelectric thin film includes (K,Na)NbO 3 . 
 
     
     
       2. The piezoelectric thin film-stacked body according to  claim 1 , wherein the second intermediate layer includes an inorganic oxide. 
     
     
       3. The piezoelectric thin film-stacked body according to  claim 1 , wherein the second intermediate layer includes a perovskite-type inorganic oxide. 
     
     
       4. The piezoelectric thin film-stacked body according to  claim 1 ,
 wherein the second intermediate layer includes at least one perovskite-type inorganic oxide selected from the group consisting of SrRuO 3 , CaRuO 3 , BaRuO 3 , and LaNiO 3 . 
 
     
     
       5. A piezoelectric thin film substrate, including:
 the piezoelectric thin film-stacked body according to  claim 1 ; and 
 a substrate, 
 wherein the first electrode layer is located between the substrate and the first intermediate layer. 
 
     
     
       6. A piezoelectric thin film device, including:
 the piezoelectric thin film-stacked body according to  claim 1 ; and 
 a second electrode layer, 
 wherein the first intermediate layer, the second intermediate layer, and the piezoelectric thin film are located between the first electrode layer and the second electrode layer. 
 
     
     
       7. A piezoelectric actuator, comprising:
 the piezoelectric thin film device according to  claim 6 . 
 
     
     
       8. A piezoelectric sensor, comprising:
 the piezoelectric thin film device according to  claim 6 . 
 
     
     
       9. A head assembly, comprising:
 the piezoelectric actuator according to  claim 7 . 
 
     
     
       10. A head stack assembly, comprising:
 the head assembly according to  claim 9 . 
 
     
     
       11. A hard disk drive, comprising:
 the head stack assembly according to  claim 10 . 
 
     
     
       12. A printer head, comprising:
 the piezoelectric actuator according to  claim 7 . 
 
     
     
       13. An ink-jet printer device, comprising:
 the printer head according to  claim 12 . 
 
     
     
       14. The piezoelectric thin film-stacked body according to  claim 1 ,
 wherein the coefficient of linear expansion of the second intermediate layer is higher than the coefficient of linear expansion of the first electrode layer, and the coefficient of linear expansion of the second intermediate layer is higher than the coefficient of linear expansion of the piezoelectric thin film. 
 
     
     
       15. The piezoelectric thin film-stacked body according to  claim 1 ,
 wherein the coefficient of linear expansion of the second intermediate layer is 0.1×10 −6  (1/K) or more higher than the larger value of the coefficient of linear expansion of the first electrode layer and the coefficient of linear expansion of the piezoelectric thin film. 
 
     
     
       16. The piezoelectric thin film-stacked body according to  claim 1 ,
 wherein the coefficient of linear expansion of the second intermediate layer is 8.0×10 −6  to 20.0×10 −6  (1/K), and the coefficient of linear expansion of the first electrode layer is 3.0×10 −6  to 15.0×10 −6  (1/K), and the coefficient of linear expansion of the piezoelectric thin film is 3.0×10 −6  to 11.0×10 −6  (1/K).